After following the battery threads, and doing what everyone else seems to have done, the one thing that worked for ME was to turn off Auto Brightness for the back light and set the slider between 1/3 and 1/2. Battery drain is now like it was in iOS 4. Oddly, my wife and I have iP4's, hers is 16G and mine is 32G. Her battery drain is the same without doing all these changes. Mine dropped like a brick, but it's better now with the above setting.